1. Field of the Invention
The present invention relates to a light emitting element structure, and more particularly, to a light emitting element structure capable of increasing light extraction efficiency and light divergence angle.
2. Description of the Prior Art
Since light emitting diodes (LEDs) have advantages of long service life, small size and low power consumption, the light emitting diodes are widely used in various kinds of illumination devices and display devices. Generally, a light emitting diode structure usually comprises a light emitting unit and a package unit. The light emitting unit is a light emitting diode die for emitting light. The package unit covers the light emitting unit, and may comprise wavelength conversion particles for converting a wavelength of light emitted from the light emitting unit.
However, in the light emitting diode structure of the prior art, a difference between a refractive index of the package unit and a refractive index of air is large, such that partial light emitted from the light emitting unit is totally reflected by an interface between the package unit and air. Therefore, the light emitting diode structure of the prior art has lower light extraction efficiency. Moreover, the light emitting diode structure of the prior art also has a smaller light divergence angle, so as to decrease illumination efficiency of the light emitting diode structure.